The present technique relates generally to interventional and surgical medical procedures. In particular, the present technique relates to image-guided therapy techniques, such as those used in conjunction with various surgical or radiological procedures.
As medical imaging technologies have matured, it has become possible to combine the use of medical imaging techniques with the performance of invasive procedures. For example, interventional procedures such as biopsies and tumor ablations may benefit from the use of imaging techniques that allow a clinician to visualize the target region along with the intervention device while the procedure is being performed. In this way, the clinician may guide the interventional device to the target region with relative accuracy, low reliance on continuous x-ray updates and, perhaps, without unnecessary tissue damage.
In general, an image may be displayed on a monitor to provide position information to an operator, such as a clinician. The image may include a visualization of the patient's anatomy along with a graphical representation of the interventional or surgical device. As the device is positioned with respect to the patient's body, the displayed image is updated to reflect the correct device coordinates. The base image of the patient's anatomy may be generated either prior to or during the medical procedure. For example, any suitable medical imaging technique, such as X-ray, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), single positron emission computed tomography (SPECT) and ultrasound, may be utilized to provide the base image displayed during tracking. The combination of the base image and the representation of the tracked device provides positioning information that allows a medical practitioner to manipulate a device to a desired position and/or associate information gathered to a precise location.
In practice, such image-guided therapy techniques typically employ a tracking frame of reference device placed proximate to the anatomy of interest. The reference device moves with the patient to provide accurate and consistent tracking of the anatomy of interest. Such image-based navigation systems typically perform a registration to align the coordinate system of the medical image to the tracking device. For example, traditional registration methods require the operator to identify anatomical or fiducial locations on the patient (e.g., point-pair, skin or tissue surface, and the like). For some procedures, this process can be time consuming, laborious, and the accuracy can be insufficient due to the user variability involved. For minimally invasive surgical (MIS) procedures, especially in the spine, there is a further limitation in that the anatomy of interest is not easily accessible for point-pair or surface registration methods.